SON - Real time Dynamic Optimization for Small Cell Rollouts

SON is one of the major focus areas for operators today; operators see it as a mandatory feature for small cell deployments. Their reasoning is that RF network planning has become complex, compared to what it was for a static definition for a macro-cell network. With the large number of small cells, and even Wi-Fi access points constituting the HetNet or Heterogeneous Networks, there is a need to optimize the effort of RF planning. Coupled with this, real time dynamic optimization or healing of the network is becoming crucial as well.

That’s where SON comes in…and that’s why operators see SON as a mandatory function as they rollout small cells. Keep in mind, SON is a very wide term. We are talking about different aspects of how SON could be applied to HetNets and how SON brings advantages to the small cell rollout. SON was initially seen as a necessary feature for the configuration and provisioning of small cells without much operator intervention. We call it the self-configuration aspect of SON, where you’re looking at the configuration of the PCIs and resolution of any confusion because of PCI collision.

Another aspect of self-configuration is Zero Touch function: when the consumer – in a residential case for example – can take the small cell box and plug it in inside the home, and start-up is all automated. Self-configuration extends further so that the consumer is able to remotely download the software and the patches without any manual intervention. So for the operators, it’s all about handling the scale factor with small cells while maintaining the OPEX: there will be a large number of these base stations entering the network and there is only so much that the operators can control manually. SON Self Configuration translates into less operating costs for the operators. The other two SON functions include Self Optimization and Self Healing – which will also benefit operators in the long-run.The SON solution can be incorporated in three different ways:

CentralizedSON solutions where SON algorithms are executed in the OAM.In such solutions SON functionality resides in a small number of locations, at a high level in the architectureMore control for operator (less scalable)

Distributed- SON solutions where SON algorithms are executed at the network element (eNB).- In such solutions SON functionality resides in many locations at a relatively low level in the architecture- Less control for operator (most scalable)

Hybrid- SON solutions where some of the SON algorithms are executed in the OAM system, while others are executed at the network element level- Best option, most suited for adhoc networks (for Femto / small cells)- Operator can “move” to Distributed option as and when they have more confidence on SON algorithms

Here are some of my responses to questions that were asked during a recent webinar:Q. Do you think SON will eliminate the need for radio planning?Renuka Bhalerao. I see that SON is actually making radio planning much more efficient. So we’re saying that radio planning will still be needed. The HetNet doesn’t exclude the macros at all. SON just makes it easier for the operators to add small cells. So it’s just the next level of optimized radio planning.Q. I would like also to ask you about the trust level that operators have in SON solutions. Where we are on that, and what sort of progress are we making?Renuka Bhalerao. Very good progress, I’ll say again, bringing it back to the network deployment that we are participating in at various operators with our solution. We are at an advanced stage of field trials and deployments inKorea, China and North America with our LTE small cells solution. The practical challenges around signaling interference that operators have seen make them want to take SON solutions such as eICIC algorithms to the actual product stage. So it’s not something that they’re shying away from or just evaluating in labs right now and trying to validate. They are actually making it part of their product as we speak.

Renuka Bhalerao

Renuka Bhalerao is Principal Systems Architect for software and solutions at Radisys with her primary focus on 3G and LTE wireless technologies. Prior to Radisys, Renuka worked as a Senior Architect at Continuous Computing and previously at Intel Corporation. As a Senior Architect at Continuous Computing Renuka was focused on the company’s Trillium Software product line. Renuka has an extensive experience working in Telecom Software and Systems with expertise in wireless and VoIP areas. Renuka holds a bachelor’s degree in Computer Science and Engineering from Regional College of Engineering, India.